Electrical switch



Oct. 18, 1932. I J, c, BOGLE 1,883,245

ELECTRICAL SWITCH Original Filed NOV. 23, 1927 g (fa/7w C 536 Xh V bi/ Patented Oct. 18, 1932 UNITED srA'rss PATENT OFFICE JOHN C. BOGLE, 0! ma FOREST, ILLINOIS, ABSIGNOB, BY IEBNE nssremn'rs, 1o MINNEAPOLIS-HONEYWELL REGULATOR OOKPAIRY, OI IIHNEAPOLIB, IINNESOTA,

A CORPORATION 01 DELAWARE nmc'rarcaiswircn Original application filed November 28,

This application is a division of ap lication Ser. No. 235,147 filed Nov. 23, 192 for electrical switches by the applicant of this application and relates to claims 7 to 15 inelusive.

This invention relates to electrical switches and has special reference to thermostatically controlled switching means.

More particularly, this invention relates to tiltable switches which are thermostatically operated and require a minimum amount of energy for their control. The device of this invention is used in instances where it is desired to eifect a circuit change at'a predetermined time, that is, to control the period between the occurrence of a certain event and the time when the switch shall change the circuit connections.

One of the particular uses of this invention is in connection with an electrical circuit employin other switching appliances for the normal control of a system, the present device to operate only when the system does not function norma ly, whereu on it will act alone to control the electrical circuit. After its influence has beenapplied in the circuit,

a change of circuit connection therethrough is not possible except by manual restoration which precludes'the possibility of the system becomingoperative. until the operator has been given due notice of the failure thereof, whereu on this defective condition may be corrected.

One of the objects of this invention is to provide an electrical switch for use in a s S? tem employing other electrical switc es which will operate to control the electrical cir uit upon the failure of the other switches therein.

Another object of this invention is to rovide an electrical switch for use as a sa ety control in an electrical circuit employing other switches whereby when said safety switch is operated into an open circuit 081- tion, it can only be restored to a close circuit )osition by manual means.

A iurthcr object of this invention is to provide a simple electrical timed switch which is durable and requires but a minimum of electrical energy for its operation.

108", Serial I0. $35,147. Divided. and thil 7-, 1828. Serial I0. 830,887.

crab y Other objects and adysantages will be aparent from the description and drawingorming a part of this specification to which latter reference may nqw be had for a more complete understanding of the characteristic features-of this invention, in which drawappllcation filed January tion of the locking mechanism for the electrical switch.

Referring now more particularly to the drawing, an electrical switch is shown embodying the device of this invention and com rises a casing 10 with a cover 11 prefpivotally secured thereto. The casing in t is instance is formed of sheet metal, although it is to be understood that any desirable casing or housing formed of any suitable material ma be employed effectively. A mounting p ate 12 is suitably secured to the rear wall of the casing 10 and in a s aced relation therewith. The entire -switching mechanism is mounted on this mountin plate thereby facilitating the assembly t ereof.

A tiltable mercury contactor switch 13 is mounted in a clip 14 which latter is in turn fixedly mounted on a latch plate 15 within.

the upper portion of the casing 10. The latch plate 15 is pivotally mounted referably at a lower right hand portion t ereof,

as at 16, to a bracket 17 secured to a preferably horizontally extending bimetallic ele-.

ment 18. A heating element 20, referably of an arcuate shape, is positioned elow and preferably adjacent the free end of the bimetallic element 18, the heating element being secured to the bimetallic element by means of a bolt 21 in a manner to obtain a good thermal'contact therebetween. Being of an arcuate sha e, the heating element will not interfere wit the mechanical operation of the bimetallic element. The heat responsive or bimetallic element 18 is preferly fixedly mounted at one end thereof to a channel-she ed bracket 23 and is preferably ada ted to ex upwardly uponreceiving an app ication of heat. The bracket 23 is fixe mounted to the mounting plate 12.

Z screw member 24 in threaded engagement with the upper side of the bracket 23 bears against the underside of the heat responsive element 18 at a point adjacent the fixed end thereof. The screw 24 is provided with a lock nut on the underside of the support 23 which holds the screw in a locked position. It will thus be seen that the entire switching mechanism including the latch plate 15, contactor 13, heating element 20 and the heat responsive element 18 are adjustably supported between the fixed end of the bimetallic element 18 and the upwardly extending portion of the screw 24. In the operation of this adjustable element, should t e screw 24 be extended a greater distance through the support 23, the bimetallic element 18 would be raised, whereby a lesser tilt of the mercury contactor tube is necessary in order to complete a circuit therethrough.

Conversely, should the screw 24 be caused to recede in its movement, the bimetallic element 18 would lower, whereby a greater degree of tilt is necessary in order to obtain an electrical circuit throu h the contactor 13. This action will be rea ily apparent upon a more complete description of the tiltable contactor 13 which will now be described.

The mercury tube contactor 13 comprises an elongated hermetically sealed container having a pair of spaced cooperating electrodes disposed therein and adjacent to one end thereof and a compact and coherent body of current conducting fluid such as mercury also-disposed therein. The contactor 13 being fixed upon the latch plate 15 will move therewith and be tilted thereby when the latch plate is pivoted at its pivotal point 16. When the contactor is thus tilted the mercury will either flow to bridge the electrodes and make an electrical circuit therethrough or will flow away therefrom to break the electrical circuit therethrou h.

The late plate 15 preferably comprises a pair of rectangularly shaped plates having a horizontally extending portion 25 preferably integral therewith and disposed on the upper end thereof and on the side 0 posite to the pivot 16. The-bracket 17 is i re erably disposed between the two plates 0 the latch plate inorder to properly support the latch plate in its vertical position, the bracket extending a substantial distance into the space between the plates and providing a substantial surface contact with the two plates.

After having obtained an open circuitthrough the contactor, it is desirable that the contactor cannot be restored to a normal operative position unless manually restored, and, therefore, an L-shaped aperture 26 is provided on the edge opposite to the extension 25 and above the pivot 16. A post 27 is secured to the mounting plate 12 and has a reduced portion thereon for engagement with the aperture 26, the shoulder formed by the reduced portion serving as a guide. In the normal position of the latch plate 15 the reduced portion engages the top of the vertically extendin portion of the aperture 26 and holds the Iatch plate in a osition such as is shown in Fig. 4 of the rawing. In the operation of this switching mechanism, a flexing or warping of the bimetallic element 18 in an upwardly direction will cause the latch plate 15 to move upwardly until the reduced portion of the post 27 engages the horizontally extending portion of the slot 26, whereafter the plate 15 will tilt on the pivot 16 to a position such as is shown in Fig. 3 of the drawing, the reduced 27 now occupying a position in the horizontally extending portion of the aperture 26, and the extension 25 resting on an arm 28. In this position, it will be noticed that the latch plate 15 is locked between the arm 28 and the pivot 16, and a further movement of the heat responsive elements is not possible in either direction. In order to release the latch plate 15 from its locked position, it is necessary to pivot the plate 15 about the pivotal point 16 where it is guided by the horizontally dis osed portion of the aperture 26 until the re uced portion of the post 27 engages the vertica 11y;

the a rture 26, w reafter the latch will portion of the post extending portion of drop into its normal position as indicated in a Fig. 4. Although it will be apparent that the weight of the latch plate 15 and the contactor 13 will cause the plate to drop to the position of Fig. 3 when actuated by the bimetallic member 18, still this action is positive for the reason that the L-shaped aperture acts as a cam to force the latch plate to drop.

In order to manually reset the latch plate when operated into an open circuit position, the arm 28 is pivotally mounted at one end thereof to a support 29 which. latter is sooured to the mounting plate 12. A rod 30 is adjustably secured at its lower end to the arm 28 and extends upwardly therefrom through the casing 10. knob 31 is secured to the rod 30 on the outside of the casing and limits the downward movement of the rod 30,

' and, therefore, the arm 28] In Fig. 1 of the drawing, the contactor 13 is shown in an off position, the heat responsive element 18 having pivoted the latch plate 15 to a position where the extension 25 abuts the arm 28,

' as shown in Fig. 3. By manually pulling the knob 31 in an upwardly direction, the latch plate 15 is pivoted about the pivotal closed circuit therethrough.

point 16 and restored to its normal rative position wherein the contactor 13 0 tains a The remaining operating mechanism shown in the casing is not an essential part of the present application and a brief summary, therefore, will hereinafter be described, a more complete understanding thereof being had b reference to a co-pending application Serial No. 235,147 of which the present application is a division.

A tiltable mercury, tube contactor switch 32, similar in all respects of operation to the previously described tiltable switch 13, is mounted on an armature 33 actuated by an electromagnet 34 substantially of the horreshoe type. A pair of coils 35 and 36 are disposed on the vertically extending arms of the core of the electromagnet and will hereafter be referred to as a pull coil and a hold coil,re spectivel In the operation of this mechanism just described, the pull coil 35 is energized to cause the armature 33 to move to one position wherein the mercury bridges the electrodes of the tiltable switch 32 to complete the circuit therethrough. Prior to the de-energization of the pull coil 35, the hold coil 36 is energized to hold the armature in the position previously referred to. After the hold coil is de-energized, as weighted member 37 disposed on one side of the armature 33 overbalances the latter to cause the same to swing back to a normal position such that the mercury in the contactor 32 flows away from the electrodes therein to break the electrical circuit therethrough.

In the normal operation of a control circuit for operating most any heating system or the like, the current is passed through the heating element and thence through the pull coil to start the operation of'the motor and the ignition means. After a predetermined interval and all conditions are nor mal, the ignition means and the pull coil 35 will be disconnected from the line and the electrical current will be shunted around the element 20. However, should an abnormal condition of the circuit obtain, the current supply to the motor and other devices in the control circuit will all continue to flow through the resistance element of the heat coil 20 for an undue length of time and thus cause the resistance element to 'heat the bimetallic actuating member 18 thereby tilting the contactor 13 to an open circuit position.

The above system is merely one of numbers of systems in which the lock switch of the present invention may .be employed. After an abnormal condition of the electrical circuit is obtained it is not desirable, of course, to continue the cycles of operation until the attendant is made aware of the conditions of the system. After such conditions are remedied, the attendant may then pull right and establish an electrica lever 31 into a position such that the contactor 13 is raised to tilt the mercur to ,the circuit through the contactor. The normal cycle of operation of the system may thereafter obtain.

While but a single embodiment of this invention is herein shown and described, it is to be understood that the same is not to be limited to that specific construction shown since various modifications may occur to those skilled in the art without departing from the spirit and scope of this invention.

I claim:

1. In a device of the characterdescribed, an actuatiiig element, .a plate pivotally mounted on said actuating element, a tiltable liquid switch mounted on said plate and operated thereby to obtain a change of circuit through said switch, said plate having a slot therein, and a pin engaging said slot for holding said plate in a fixed osition after obtaining a change of circuit connection through said switch whereby said plate is restorable by manual means only.

2. In a device of the character described, an actuating element, .a plate pivotally mounted upon said actuating element, a tiltable liquid switch mounted on said plate and actuated thereby to obtain a change of circuit connection through said switch, said plate having a substantially L-shaped slot therethrough, a pin for engaging said slot for holding said plate in a fixed position after obtaining a change of circuit connection through said switch whereby said plate is restored by manual means only.

3. In a device of the character described, a thermally operated actuating member, a plate ivotally mounted upon said actuating memer, a tiltable liquid switch mounted on said plate and actuated thereby to obtain a chan e of circuit connection through saidswitcIi, said plate having a substantially L-shaped slot therethrough, a pin for engaging one portion of said slot when said plate is in one position and for engaging a second portion of said slot when said plate is actuated into a second position whereby said plate is restorable by manual means only.

4. In a device of the character described, a thermally operated actuating member, a plate pivotally mounted upon said actuating member, a tiltable liquid switch mounted on said plate and actuated thereby to obtain a change of circuit connection through said switch, said plate having a slot comprising vertically and horizontally extending portions, a pin for engaging said horizontally extending portion in a normal operating position and for en aging said vertically extending portion a ter a changed position of said plate whereby said plate is restored to its normal operating position by manual means only.

mounted thereon, a thermal responsive member fixed at one end and holding at its other endwhen not overheated said movable memher in normal operating sition and said switching means in close circuit position, means for heating said thermal responsive member whereupon when it becomes distorted beyond a redetermined point it will allow. said switcli matically to open circuit position, and manual means for restoring said members to their .normal operating sitions.

7. In a device of the c aracter described, a movable member, electric switching means mounted thereon, a thermal responsive actuator member supporting said movable member in normal operating position when the former is not heated beyond a predetermined degree, an electrical heater for heating said thermal actuator member which when heated beyond a predetermined. degree becomes distorted to allow said electric switching means to move automatically to another circuit position and manual means for restoring said members to their normal operating ositions.

8. In a evice of the characted described,

' a pivotally mounted member, electric switchallows said electric switc ing means thereon, a bimetallic member fixed at one end and supporting at its other end said pivotally mounted member whereby said electric switching means ma be held in normal operating position, an e ectric heater for influencing said bimetallic member which when distorted beyond a predetermined point ing means to move automatically to open circuit sition, and manual means forrestoring sai members to their normal operating. positions.

9. In a device of the character described, a movable member, a mercu electric'contactor mounted thereupon, a bimetallic member fixed at one end and supporting at its other end said movable member whereby said mercury electric contactor isv held in normal operating sition, an electric heater for influencing sai bimetallic member which when distorted beyond. a predetermined point allows said mercury electric contactor to move automatically to another circuit posiber in normal operating ing means to move autoanother circuit in normal operating position, means for heating said thermal responsive member whereupon when it is distorted be 0nd a predetermined point it will allow said electric switching means to move automatically to another circuit position,'a casing enclosing all of said parts, and means operable manually from outside said casing for restoring norma operating position.

11. In a device of the character described, a. movable member, electric switching means mounted thereon, a thermal responsive member fixed at one end and holding at its other end when not overheated said movable memosition and said switching means in norma circuit position, means for heating said thermal responsive member whereupon when it becomes distorted beyond a redetermined point it will allow said switc ing means to move automatically to another circuit position, a casing enclosing all of said parts, and manually operable means extending exteriorly of said casing for restoring said switching means to its normal operating osition.

- 12. In a device of the c aracter described, a movable'member, electric switching means mounted thereon, a thermal responsive actu-.

said electric switching means to its ator connected to said movable member for holdin the latter in normal operating position w en the former is not heated beyond .a predetermined degree, an electrical heater for heating said thermal actuator which when heated beyond a predetermined degree becomes distorted to allow said electric roe switching means to move automatically to osition, andmanual means for restoring said electric switching means to its normal operating position.

13'. In a device of the character described, a movable member, electric switching means thereon, a bimetallic'element adjustab y fixed at one endand su porting atits other end said movable mem r whereb said electric switching meansv maybe he d in normal operating position, an electric heater for in fluencin said bimetallic element which when distorte beyond a certain degree determined by the adjustment of its fixed end allows said electric switching means to move automatically to another circuit position, and 1 manual means for restoring said electric switching means to its normal operating JOHN onoenn. 

